Expression of the Meiosis-Specific Synaptonemal Complex
Protein 1 in a Heterologous System Results in the Formation of
Large Protein Structures

AbstractThe synaptonemal complex is a meiosis-specific structure
essential for synapsis of homologous chromosomes. The
synaptonemal complex protein 1 (SCP1) is a major constituent of
the transversal filament, a fibrous structure that connects the
central element of the synaptonemal complex with the two lateral
elements. The SCP1 protein forms filamentous dimers with the two
molecules that have the same polarity, with the C-termini being
anchored in the lateral elements and the N-termini reaching into
the central element. We investigated whether the SCP1 protein can
take part in the formation of higher order protein structures by
expressing it in a heterologous system. We find that expression
of SCP1 in Swiss-3T3 fibroblast cells results in the formation of
large protein structures. These protein structures resemble a
higher order protein structure produced by overexpression of a
yeast transversal filament protein in meiotic cells. Our results
show that SCP1 is a structural protein and that it most likely is
directly involved in the assembly of the synaptonemal
complex.